69% blockage of carotid artery

The TIA would have been cerebral, so internal to the skull proper, and upstream of any stenosis. The stenosis is more recent than the 15 years, so the TIA had nothing to do with the stenosis in the carotid.
The pain in your chest and arms could have been several things, but if you're concerned about it being coronary, that, too, would be unrelated to the carotid stenosis higher up in the neck, and not in the chest where the heart is. If you feel the chest pain was related to your heart, it could be that you have stenosis in one or more coronary arteries, and this would be reflected, presumably, in a recent CAC score. Have you had a CAC test? If it turns out that you have substantial deposition of arterial plaque in the coronary arteries, then there's a good chance your chest pain is angina, especially if it sometimes radiates out into the armpits. https://my.klarity.health/angina-and-armpit-pain/
The pain in your arm, if that's solely where it was, and NOT in the chest, was possibly a simple spasm....? Ligamental stretching or tearing, possibly related to age or to unusual use of that tissue (if you ride seldom, or were straining on a hill?) This is just a guessing game here on this forum.
I suggest that, if you get angina, this needs to be reported to your doctor or cardiologist. The blockage in your carotid will need to be addressed soon, possibly within the next year...on the advice of a qualified cardiologist or vascular surgeon.

Thank you so much for your detailed information, I really appreciate this. I am so appreciate this .
My arm hurts when I am at the end of my strenuous bike ride, sometimes my hand will become numb but I think it could be caused by the way I grip my handles. I am 74 but ride 8-10 miles 5x a week and not at a slow speed. I don’t have any pain in my chest. My cardiologist just wanted to prescribe 1 baby aspirin a day but I’ve read if your carotid is blocked by 70 %, you should take further precautions. After I read this I asked my cardiologist to please look further into this. He is now referring me to a vascular surgeon, thank God! My father had a stroke and was totally debilitated. I do not want that . Again, thank you for your help

70% is the magic number for blockages but also consider that is you’ve got one blockage where else you might have others? It is great that you’re able to bike that far and you sound in good health otherwise. The doctors just covering his butt by giving you something to help keep your blood flowing. Let us know your consult outcome?

Thank you, I’ll let you know.